1. Field of the Invention
This application relates to orthodontic appliances capable of applying a primary force to a jaw, the reaction from which force is applied to the exterior of the head and/or neck by an extraoral force-reaction device.
2. Prior Art
A device for applying primary force to a jaw by an intraoral device and exerting the reaction force on an extraoral force-reaction device engageable with the wearer's head or neck is shown, for example, in the Armstrong U.S. Pat. No. 3,526,035. The appliance of the present invention constitutes an improvement over the apparatus shown in that patent. A device for applying a constant force to an intraoral device utilizing a negator is shown in McVickers et al. U.S. Pat. No. 3,686,757. Patents showing orthodontic headgear including yoke bows are Interlandi U.S. Pat. No. 3,203,099 and DeWoskin U.S. Pat. No. 3,571,930, FIG. 3.